Acute inflammation induced by intramyocardial injection of zymosan A, a Toll-like receptor 2 (TLR2) agonist, was shown to prevent tissue injury and increase endogenous cardiomyocyte proliferation in an adult MI injury model, which suggests that the acute immune response is sufficient to stimulate cardiomyocyte proliferation (28). This evidence concerns the gene TLR2 and myocardial infarction.